#!/bin/bash
#
# This script configures basic settings and install standard tools on your Proxmox VE Server with ZFS storage
# 
# Features:
# + Configure ZFS ARC Cache
# + Configure vm.swappiness
# + Install and configure zfs-auto-snapshot
# + Switch pve-enterprise/pve-no-subscription/pvetest repo
# + Disable "No subscription message" in webinterface in no-subscription mode
# + Add pve-enterprise subscription key
# + Update system to the latest version
# + Install common tools
# + Install Proxmox SDN Extensions
# + Configure automatic backup of /etc Folder
# + Configure locales
# + SSH server hardening
# + Install checkzfs
# + Install bashclub-zsync
# + Create zfspool storage for swap disks if not exists
# + Adjust default volblocksize for Proxmox zfspool storages
# + Configure proxmox mail delivery with postfix
# + Daily check (and download) for new stable virtio-win iso and prune old (unused) versions
#
#
# Author: (C) 2023 Thorsten Spille <thorsten@bashclub.org>

set -uo pipefail

#### INITIAL VARIABLES ####
PROG=$(basename "$0")

# Required tools for usage in postinstall
REQUIRED_TOOLS="curl ifupdown2 git gron ipmitool libsasl2-modules lsb-release libpve-network-perl postfix ssl-cert zfs-auto-snapshot"

# Optional tools to install
OPTIONAL_TOOLS="dnsutils ethtool htop iftop jq lshw lsscsi mc net-tools nvme-cli rpl screen smartmontools sudo sysstat tmux unzip vim"

# Settings for Backup of /etc folder
PVE_CONF_BACKUP_TARGET=rpool/pveconf
PVE_CONF_BACKUP_CRON_TIMER="3,18,33,48 * * * *"

# Round factor to set L1ARC cache (Megabytes)
ROUND_FACTOR=512

# get total size of all zpools
ZPOOL_SIZE_SUM_BYTES=0
for line in $(zpool list -o size -Hp); do ZPOOL_SIZE_SUM_BYTES=$(($ZPOOL_SIZE_SUM_BYTES+$line)); done

# get information about available ram
MEM_TOTAL_BYTES=$(($(awk '/MemTotal/ {print $2}' /proc/meminfo) * 1024))

# get values if defaults are set
ARC_MAX_DEFAULT_BYTES=$(($MEM_TOTAL_BYTES / 2))
ARC_MIN_DEFAULT_BYTES=$(($MEM_TOTAL_BYTES / 32))

# get current settings
ARC_MIN_CUR_BYTES=$(cat /sys/module/zfs/parameters/zfs_arc_min)
ARC_MAX_CUR_BYTES=$(cat /sys/module/zfs/parameters/zfs_arc_max)

# get vm.swappiness
SWAPPINESS=$(cat /proc/sys/vm/swappiness)

# zfs-auto-snapshot default values
declare -A auto_snap_keep=( ["frequent"]="12" ["hourly"]="96" ["daily"]="14" ["weekly"]="6" ["monthly"]="3" )

setblocksize=0
volblocksize=16k

# gather proxmox subscription info
serverid=$(pvesubscription get | grep serverid | cut -d' ' -f2)
sub_status=$(pvesubscription get | grep status | cut -d' ' -f2)

# get notification address
recipientaddress=$(pvesh get access/users/root@pam --output-format yaml| grep email | cut -d' ' -f2)

#### FUNCTIONS ####

log(){
    echo "$(date) $1"
}

roundup(){
    echo $(((($1 + $ROUND_FACTOR) / $ROUND_FACTOR) * $ROUND_FACTOR))
}

roundoff(){
    echo $((($1 / $ROUND_FACTOR) * $ROUND_FACTOR))
}

isnumber(){
    re='^[0-9]+$'
    if ! [[ $1 =~ $re ]] ; then
        return 1
    else
        return 0
    fi
}

inputbox_int(){
    cancel=0
    while true; do
        if ! out=$(whiptail --title "$1" --backtitle "$PROG" --inputbox "$2" $3 76 $4 3>&1 1>&2 2>&3) ; then
            cancel=1 ; break 
        fi
        if isnumber $out; then
            break
        fi
    done
    echo $out
    return $cancel
}

cancel_dialog() {
    whiptail --title "CANCEL POSTINSTALL" --backtitle $PROG --msgbox "Postinstall was cancelled by user interaction" 8 76 3>&1 1>&2 2>&3
    exit 127
}

arc_suggestion(){
    if [ $ARC_MIN_DEFAULT_BYTES -lt 33554432 ]; then ARC_MIN_DEFAULT_MB="32" ; else ARC_MIN_DEFAULT_MB="$(($ARC_MIN_DEFAULT_BYTES / 1024 / 1024))" ; fi

    ZFS_ARC_MAX_MEGABYTES=$(roundup $(($ZPOOL_SIZE_SUM_BYTES / 1024 / 1024 / 1024)))
    ZFS_ARC_MIN_MEGABYTES=$(roundoff $(($ZPOOL_SIZE_SUM_BYTES / 2048 / 1024 / 1024)))
    if [ $ZFS_ARC_MIN_MEGABYTES -eq 0 ]; then
        ZFS_ARC_MIN_MEGABYTES=$(($ZFS_ARC_MAX_MEGABYTES / 2))
        if [ $ARC_MIN_DEFAULT_MB -gt $ZFS_ARC_MAX_MEGABYTES ]; then
            ZFS_ARC_MIN_MEGABYTES=$ARC_MIN_DEFAULT_MB
        fi
    fi

    if [ $ARC_MIN_CUR_BYTES -gt 0 ]; then ARC_MIN_CURRENT_MB="$(($ARC_MIN_CUR_BYTES / 1024 / 1024))" ; else ARC_MIN_CURRENT_MB="0" ; fi
    if [ $ARC_MAX_CUR_BYTES -gt 0 ]; then ARC_MAX_CURRENT_MB="$(($ARC_MAX_CUR_BYTES / 1024 / 1024))" ; else ARC_MAX_CURRENT_MB="0" ; fi

    if ! whiptail --title "CONFIGURE ZFS L1ARC SIZE" \
    --backtitle $PROG \
    --yes-button "Accept" \
    --no-button "Edit" \
    --yesno " Summary: \n \
    System Memory: $(($MEM_TOTAL_BYTES / 1024 / 1024)) MB\n \
    Zpool size (sum): $(($ZPOOL_SIZE_SUM_BYTES / 1024 / 1024)) MB\n \
\n \
Note: zfs_arc_min must always be lower than zfs_arc_max! \n\n \
The L1ARC cache suggestion is calculated by size of all zpools \n\n \
Suggested values: \n \
    zfs_arc_min: $(($ZFS_ARC_MIN_MEGABYTES)) MB (default: $ARC_MIN_DEFAULT_MB MB, current: $ARC_MIN_CURRENT_MB MB)\n \
    zfs_arc_max: $(($ZFS_ARC_MAX_MEGABYTES)) MB (default: $(($ARC_MAX_DEFAULT_BYTES / 1024 / 1024)) MB, current: $ARC_MAX_CURRENT_MB MB)\n" 17 76; then
        arc_set_manual
    fi
}

arc_set_manual() {
    if [ $ARC_MIN_CURRENT_MB -gt 0 ]; then MIN_VALUE=$ARC_MIN_CURRENT_MB; else MIN_VALUE=$ZFS_ARC_MIN_MEGABYTES; fi
    if [ $ARC_MAX_CURRENT_MB -gt 0 ]; then MAX_VALUE=$ARC_MAX_CURRENT_MB; else MAX_VALUE=$ZFS_ARC_MAX_MEGABYTES; fi

    if ! ZFS_ARC_MIN_MEGABYTES=$(inputbox_int 'CONFIGURE ZFS L1ARC MIN SIZE' 'Please enter zfs_arc_min in MB' 7 $MIN_VALUE) ; then cancel_dialog ; fi
    if ! ZFS_ARC_MAX_MEGABYTES=$(inputbox_int 'CONFIGURE ZFS L1ARC MAX SIZE' 'Please enter zfs_arc_max in MB' 7 $MAX_VALUE) ; then cancel_dialog ; fi
}

vm_swappiness () {
    if ! SWAPPINESS=$(inputbox_int "CONFIGURE SWAPPINESS" "Please enter percentage of free RAM to start swapping" 8 $SWAPPINESS) ; then cancel_dialog ; fi
}

auto_snapshot(){
    if dpkg -l zfs-auto-snapshot > /dev/null 2>&1 ; then
        for interval in "${!auto_snap_keep[@]}"; do
            if [[ "$interval" == "frequent" ]]; then
                auto_snap_keep[$interval]=$(cat /etc/cron.d/zfs-auto-snapshot | grep keep | cut -d' ' -f19 | cut -d '=' -f2)
            else
                auto_snap_keep[$interval]=$(cat /etc/cron.$interval/zfs-auto-snapshot | grep keep | cut -d' ' -f6 | cut -d'=' -f2)
            fi
        done
    fi
    for interval in "${!auto_snap_keep[@]}"; do
        if ! auto_snap_keep[$interval]=$(inputbox_int "CONFIGURE ZFS-AUTO-SNAPSHOT" "Please set number of $interval snapshots to keep" 7 ${auto_snap_keep[$interval]}) ; then cancel_dialog ; fi
    done
}

select_subscription(){
    suppress_warning=0
    if [[ $sub_status == "notfound" ]] || [[ $sub_status == "invalid" ]]; then
        if [[ $repo_selection == "pve-enterprise" ]]; then
            if whiptail --title "NO PROXMOX SUBSCRIPTION FOUND" \
            --backtitle $PROG \
            --yes-button "ADD" \
            --no-button "SKIP" \
            --yesno "Server ID: $serverid\n\nDo you want to add a subscription key?" 9 76 ; then
                input_subscription
            fi
        else
            if whiptail --title "NO PROXMOX SUBSCRIPTION FOUND" \
            --backtitle $PROG \
            --yes-button "SUPPRESS WARNING" \
            --no-button "SKIP" \
            --yesno "Do you want to suppress the no subscription warning in WebGUI?" 9 76 ; then
                suppress_warning=1
            fi
        fi
    fi
}

ask_locales(){
    if ! locales=$(whiptail --title "SET LOCALES" --backtitle "$PROG" --inputbox "Please enter a space separated list of locales to generate." 9 76 "$(echo $(grep -vE '#|^$' /etc/locale.gen | cut -d ' ' -f1))" 3>&1 1>&2 2>&3); then cancel_dialog ; fi
}

ask_ssh_hardening(){
    ssh_hardening=0
    if whiptail --title "HARDEN SSH SERVER" \
    --backtitle "$PROG" \
    --yes-button "HARDEN SSH SERVER" \
    --no-button "SKIP" \
    --yesno "Do you want to apply the SSH hardening profile?\nHost-Keys will be changed and root-Login with password will be disabled." 9 76 ; then
        ssh_hardening=1
    fi
}

input_subscription(){
    key=""
    cancel=0
    while [[ $key == "" ]]; do
        if ! key=$(whiptail --title "ADD PROXMOX SUBSCRIPTION KEY" --backtitle "$PROG" \
        --inputbox "Server ID: $serverid\n\nAdd your subscription key" 9 76 3>&1 1>&2 2>&3) ; then
            cancel=1 ; break
        fi
    done
    if [ $cancel -eq 0 ]; then
        set_subscription $key
    fi
    return $cancel
}

set_subscription(){
    log "Setting subscription key $1"
    if ! pvesubscription set $1; then
        input_subscription
    elif [[ $(pvesubscription get | grep status | cut -d' ' -f2) == "invalid" ]]; then
        input_subscription
    fi
}

suppress_no_subscription_warning(){
    if [ $suppress_warning -gt 0 ]; then
        # remove old no-sub-hack
        if [ -f /opt/bashclub/no-sub-hack.sh ] ; then rm -r /opt/bashclub ; fi
        if [ -f /etc/apt/apt.conf.d/80bashclubapthook ] ; then rm /etc/apt/apt.conf.d/80bashclubapthook ; fi

        wget -q --no-cache -O /usr/local/bin/suppress_no_subscription_warning https://github.com/bashclub/no-sub-hack/raw/main/no-sub-hack.sh
        chmod +x /usr/local/bin/suppress_no_subscription_warning
        /usr/local/bin/suppress_no_subscription_warning
        cat << EOF > /etc/apt/apt.conf.d/80-suppress_no_subscription_warning
DPkg::Post-Invoke {"/usr/local/bin/suppress_no_subscription_warning";};
EOF
    fi
}

select_pve_repo(){
    pveenterprise=OFF
    pvenosubscription=OFF
    pvetest=OFF
    if [ -f /etc/apt/sources.list.d/pve-enterprise.list ]; then
        if grep -v '#' /etc/apt/sources.list.d/pve-enterprise.list | grep "pve-enterprise" > /dev/null ; then
            pveenterprise=ON
        else
            if [ -f /etc/apt/sources.list ]; then
                if grep -v '#' /etc/apt/sources.list | grep "pve-no-subscription" > /dev/null ; then
                    pvenosubscription=ON
                elif grep -v '#' /etc/apt/sources.list | grep "pvetest" > /dev/null ; then
                    pvetest=ON
                else
                    pveenterprise=ON
                fi 
            fi
        fi
    fi
    repo_selection=$(whiptail --title "SELECT PVE REPOSITORY" --backtitle "$PROG" \
    --radiolist "Choose Proxmox VE repository" 20 76 4 \
    "pve-enterprise" "Proxmox VE Enterprise repository" "$pveenterprise" \
    "pve-no-subscription" "Proxmox VE No Subscription repository" "$pvenosubscription" \
    "pvetest" "Proxmox VE Testing repository" "$pvetest" 3>&1 1>&2 2>&3)

}

select_ceph_repo(){
    none=OFF
    quincyenterprise=OFF
    quincynosubscription=OFF
    quincytest=OFF
    reefenterprise=OFF
    reefnosubscription=OFF
    reeftest=OFF
    if [ -f /etc/apt/sources.list.d/ceph.list ]; then
        if grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "quincy" | grep "enterprise" > /dev/null ; then
            quincyenterprise=ON
        elif grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "reef" | grep "enterprise" > /dev/null ; then
            reefenterprise=ON
        elif grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "quincy" | grep "no-subscription" > /dev/null ; then
            quincynosubscription=ON
        elif grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "reef" | grep "no-subscription" > /dev/null ; then
            reefnosubscription=ON
        elif grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "quincy" | grep "test" > /dev/null ; then
            quincytest=ON
        elif grep -v '#' /etc/apt/sources.list.d/ceph.list | grep "reef" | grep "test" > /dev/null ; then
            reeftest=ON
        else
            none=ON
        fi        
    else
        none=ON
    fi
    ceph_repo_selection=$(whiptail --title "SELECT PVE REPOSITORY" --backtitle "$PROG" \
    --radiolist "Choose Ceph repository" 20 76 7 \
    "none" "No Ceph repository" "$none" \
    "quincyenterprise" "Ceph Quincy Enterprise repository" "$quincyenterprise" \
    "quincynosubscription" "Ceph Quincy No Subscription repository" "$quincynosubscription" \
    "quincytest" "Ceph Quincy Testing repository" "$quincytest" \
    "reefenterprise" "Ceph Reef Enterprise repository" "$reefenterprise" \
    "reefnosubscription" "Ceph Reef No Subscription repository" "$reefnosubscription" \
    "reeftest" "Ceph Reef Testing repository" "$reeftest" 3>&1 1>&2 2>&3)
}

set_locales(){
    log "Setting locales"
    for locale in $locales; do
        line=$(grep $locale /etc/locale.gen)
        if echo $line | grep "#" ; then
            sed -i "s/$line/$(echo $line | cut -d' ' -f2-)/" /etc/locale.gen
        fi
    done
    locale-gen > /dev/null 2>&1
}

set_ceph_repo(){
    log "Setting Ceph package repositories to $ceph_repo_selection"
    if [[ "$ceph_repo_selection" != "none" ]]; then
        if [[ "$ceph_repo_selection" == *"quincy"* ]]; then
            generation=quincy
        elif [[ "$ceph_repo_selection" == *"reef"* ]]; then
            generation=reef
        fi
        if [[ "$ceph_repo_selection" == *"enterprise"* ]]; then
            selection=enterprise
            server=https://enterprise.proxmox.com
        elif [[ "$ceph_repo_selection" == *"nosubscription"* ]]; then
            selection=no-subscription
            server=http://download.proxmox.com
        elif [[ "$ceph_repo_selection" == *"test"* ]]; then
            selection=test
            server=http://download.proxmox.com
        fi
        echo "deb ${server}/debian/ceph-${generation} $(lsb_release -cs 2>/dev/null) ${selection}" > /etc/apt/sources.list.d/ceph.list
    else
        rm -f /etc/apt/sources.list.d/ceph.list
    fi
}

set_pve_repo(){
    log "Setting Proxmox package repositories to $repo_selection"
    nosub=$(grep pve-no-subscription /etc/apt/sources.list)
    enterprise=$(grep pve-enterprise /etc/apt/sources.list.d/pve-enterprise.list)
    test=$(grep pvetest /etc/apt/sources.list)
    if [[ $repo_selection == "pve-enterprise" ]]; then
        echo "deb https://enterprise.proxmox.com/debian/pve $VERSION_CODENAME pve-enterprise" > /etc/apt/sources.list.d/pve-enterprise.list
        if [[ $nosub != "" ]] && [[ $nosub != *"#"* ]]; then
            sed -i "s|$nosub|# $nosub|g" /etc/apt/sources.list
        fi
        if [[ $test != "" ]] && [[ $test != *"#"* ]]; then
            sed -i "s|$test|# $test|g" /etc/apt/sources.list
        fi
    elif [[ $repo_selection == "pve-no-subscription" ]]; then
        if [[ $nosub == "" ]]; then
            echo -e "\ndeb http://download.proxmox.com/debian/pve $VERSION_CODENAME pve-no-subscription\n" >> /etc/apt/sources.list
        elif [[ $nosub == *"#"* ]]; then
            sed -i "s|$nosub|$(echo $nosub | cut -d' ' -f2-)|" /etc/apt/sources.list
        fi
        if [[ $enterprise != "" ]] && [[ $enterprise != *"#"* ]]; then
            sed -i "s|$enterprise|# $enterprise|g" /etc/apt/sources.list.d/pve-enterprise.list 
        fi
        if [[ $test != "" ]] && [[ $test != *"#"* ]]; then
            sed -i "s|$test|# $test|g" /etc/apt/sources.list
        fi
    elif [[ $repo_selection == "pvetest" ]]; then
        if [[ $test == "" ]]; then
            echo -e "\ndeb http://download.proxmox.com/debian/pve $VERSION_CODENAME pvetest\n" >> /etc/apt/sources.list
        elif [[ $test == *"#"* ]]; then
            sed -i "s|$test|$(echo $test | cut -d' ' -f2-)|" /etc/apt/sources.list
        fi
        if [[ $nosub != "" ]] && [[ $nosub != *"#"* ]]; then
            sed -i "s|$nosub|# $nosub|g" /etc/apt/sources.list
        fi
        if [[ $enterprise != "" ]] && [[ $enterprise != *"#"* ]]; then
            sed -i "s|$enterprise|# $enterprise|g" /etc/apt/sources.list.d/pve-enterprise.list
        fi
    fi
}

update_system(){
    log "Downloading latest package lists"
    apt update > /dev/null 2>&1
    log "Upgrading system to latest version - Depending on your version this could take a while..."
    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq dist-upgrade > /dev/null 2>&1
}

install_tools(){
    log "Installing toolset - Depending on your version this could take a while..."
    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq install $REQUIRED_TOOLS $OPTIONAL_TOOLS > /dev/null 2>&1
}

enable_sdn(){
    log "Enabling SDN features"
    q=$(cat /etc/network/interfaces | grep "source /etc/network/interfaces.d/*")
    if [ $? -gt 0 ]; then
        echo "source /etc/network/interfaces.d/*" >> /etc/network/interfaces
    fi
}

set_arc_cache(){
    log "Adjusting ZFS level 1 arc (Min: $ZFS_ARC_MIN_MEGABYTES, Max: $ZFS_ARC_MAX_MEGABYTES)"
    ZFS_ARC_MIN_BYTES=$((ZFS_ARC_MIN_MEGABYTES * 1024 *1024))
    ZFS_ARC_MAX_BYTES=$((ZFS_ARC_MAX_MEGABYTES * 1024 *1024))
    echo $ZFS_ARC_MIN_BYTES > /sys/module/zfs/parameters/zfs_arc_min
    echo $ZFS_ARC_MAX_BYTES > /sys/module/zfs/parameters/zfs_arc_max
    cat << EOF > /etc/modprobe.d/zfs.conf
options zfs zfs_arc_max=$ZFS_ARC_MAX_BYTES
options zfs zfs_arc_min=$ZFS_ARC_MIN_BYTES
EOF
}

set_auto_snapshot(){
    # configure zfs-auto-snapshot
    for interval in "${!auto_snap_keep[@]}"; do
        log "Setting zfs-auto-snapshot retention: $interval = ${auto_snap_keep[$interval]}"
        if [[ "$interval" == "frequent" ]]; then
            CURRENT=$(cat /etc/cron.d/zfs-auto-snapshot | grep keep | cut -d' ' -f19 | cut -d '=' -f2)
            if [[ "${auto_snap_keep[$interval]}" != "$CURRENT" ]]; then
                rpl "keep=$CURRENT" "keep=${auto_snap_keep[$interval]}" /etc/cron.d/zfs-auto-snapshot > /dev/null 2>&1
            fi
        else
            CURRENT=$(cat /etc/cron.$interval/zfs-auto-snapshot | grep keep | cut -d' ' -f6 | cut -d'=' -f2)
            if [[ "${auto_snap_keep[$interval]}" != "$CURRENT" ]]; then
                rpl "keep=$CURRENT" "keep=${auto_snap_keep[$interval]}" /etc/cron.$interval/zfs-auto-snapshot > /dev/null 2>&1
            fi
        fi
    done
}

set_swappiness(){
    log "Setting swappiness to $SWAPPINESS %"
    echo "vm.swappiness=$SWAPPINESS" > /etc/sysctl.d/swappiness.conf
    sysctl -w vm.swappiness=$SWAPPINESS > /dev/null
}

pve_conf_backup(){
    log "Configuring pve-conf-backup"
    zfs list $PVE_CONF_BACKUP_TARGET > /dev/null 2>&1
    if [ $? -ne 0 ]; then
        zfs create $PVE_CONF_BACKUP_TARGET
    fi

    if [[ "$(df -h -t zfs | grep /$ | cut -d ' ' -f1)" == "rpool/ROOT/pve-1" ]] ; then
        echo "$PVE_CONF_BACKUP_CRON_TIMER root rsync -va --delete /etc /$PVE_CONF_BACKUP_TARGET > /$PVE_CONF_BACKUP_TARGET/pve-conf-backup.log" > /etc/cron.d/pve-conf-backup
    fi
}

harden_ssh(){
    if [ $ssh_hardening -gt 0 ]; then
        log "Hardening ssh server"
        rm /etc/ssh/ssh_host_*
        log "Creating new SSH host keys"
        ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key -N "" > /dev/null 2>&1
        ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N "" > /dev/null 2>&1
        log "Creating new SSH moduli"
        awk '$5 >= 3071' /etc/ssh/moduli > /etc/ssh/moduli.safe
        mv /etc/ssh/moduli.safe /etc/ssh/moduli

        log "Writing hardened SSH config"
        if [[ $VERSION_CODENAME == "bookworm" ]]; then
            echo -e "\n# Restrict key exchange, cipher, and MAC algorithms, as per sshaudit.com\n# hardening guide.\nKexAlgorithms sntrup761x25519-sha512@openssh.com,curve25519-sha256,curve25519-sha256@libssh.org,gss-curve25519-sha256-,diffie-hellman-group16-sha512,gss-group16-sha512-,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha256\nCiphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr\nMACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com\nHostKeyAlgorithms ssh-ed25519,ssh-ed25519-cert-v01@openssh.com,sk-ssh-ed25519@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,rsa-sha2-512,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256,rsa-sha2-256-cert-v01@openssh.com" > /etc/ssh/sshd_config.d/ssh-audit_hardening.conf
        elif [[ $VERSION_CODENAME == "bullseye" ]]; then
            sed -i 's/^\#HostKey \/etc\/ssh\/ssh_host_\(rsa\|ed25519\)_key$/HostKey \/etc\/ssh\/ssh_host_\1_key/g' /etc/ssh/sshd_config
            echo -e echo -e "\n# Restrict key exchange, cipher, and MAC algorithms, as per sshaudit.com\n# hardening guide.\nKexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha256\nCiphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr\nMACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com\nHostKeyAlgorithms ssh-ed25519,ssh-ed25519-cert-v01@openssh.com,sk-ssh-ed25519@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,rsa-sha2-256,rsa-sha2-512,rsa-sha2-256-cert-v01@openssh.com,rsa-sha2-512-cert-v01@openssh.com" > /etc/ssh/sshd_config.d/ssh-audit_hardening.conf
        fi
        systemctl restart ssh.service
    fi
}

ask_mail_config(){
    mailconfig=0
    smtpauth=0
    senderaddress=""
    displayname=""
    if [ -f /etc/postfix/sender_canonical_maps ]; then
        senderaddress=$(grep "@" -m1 /etc/postfix/sender_canonical_maps | cut -d '<' -f2 | cut -d '>' -f1)
        displayname=$(grep "@" -m1 /etc/postfix/sender_canonical_maps | cut -d' ' -f5)
    fi
    smtphost=$(grep relayhost /etc/postfix/main.cf | cut -d : -f1 | cut -d ' ' -f3 | cut -d ']' -f1 | cut -d '[' -f2)
    smtpport=$(grep relayhost /etc/postfix/main.cf | cut -d':' -f2)
    if [[ $smtpport == "" ]] || [[ $smtpport == "relayhost" ]]; then
        smtpport=25
    fi    
    username=""
    password=""
    if [ -f /etc/postfix/sasl_passwd ]; then
        username=$(cat /etc/postfix/sasl_passwd | cut -d ' ' -f2- | cut -d':' -f1)
        password=$(cat /etc/postfix/sasl_passwd | cut -d ' ' -f2- | cut -d':' -f2-)
    else
        username=$senderaddress
    fi
    if whiptail --title "MAIL DELIVERY" \
    --backtitle "$PROG" \
    --yes-button "MAIL CONFIG" \
    --no-button "SKIP" \
    --yesno "Do you want to configure postfix with a smarthost?" 9 76 ; then
        mailconfig=1
        if ! displayname=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter your sender display name." 9 76 $(hostname -f) 3>&1 1>&2 2>&3); then cancel_dialog; fi
        if ! recipientaddress=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the email address to receive notifications." 9 76 $recipientaddress 3>&1 1>&2 2>&3); then cancel_dialog; fi
        if ! smtphost=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the servername of your smarthost." 9 76 $smtphost 3>&1 1>&2 2>&3); then cancel_dialog; fi
        smtpport=$(inputbox_int 'MAIL DELIVERY' 'Please enter the port of your smarthost' 7 $smtpport)
        if ! senderaddress=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter your sender email address." 9 76 $senderaddress 3>&1 1>&2 2>&3); then cancel_dialog; fi
        if whiptail --title "MAIL DELIVERY" \
        --backtitle "$PROG" \
        --yes-button "CONFIGURE AUTH" \
        --no-button "SKIP" \
        --yesno "Do you want to configure authentication against your smarthost?" 9 76 ; then
            smtpauth=1
            if ! username=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --inputbox "Please enter the username for authentication." 9 76 $username 3>&1 1>&2 2>&3); then cancel_dialog; fi
            if ! password=$(whiptail  --title "MAIL DELIVERY" --backtitle "$PROG" --passwordbox "Please enter the passsword for authentication." 9 76 $password 3>&1 1>&2 2>&3); then cancel_dialog; fi
        fi
    fi
}

set_mail_delivery(){
    if [ $mailconfig -gt 0 ]; then
        log "Configuring mail delivery"
        cat << EOF > /etc/postfix/main.cf
myhostname=$(hostname -f)
smtpd_banner = \$myhostname ESMTP \$mail_name (Debian/GNU)
biff = no
append_dot_mydomain = no
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = \$myhostname, localhost.\$mydomain, localhost
mynetworks = 127.0.0.0/8
inet_interfaces = loopback-only
recipient_delimiter = +
compatibility_level = 2

#### sasl extension
relayhost = [$smtphost]:$smtpport
smtp_tls_CAfile = /etc/postfix/cacert.pem
smtp_use_tls = yes
sender_canonical_classes = envelope_sender, header_sender
sender_canonical_maps =  regexp:/etc/postfix/sender_canonical_maps
smtp_header_checks = regexp:/etc/postfix/header_check
EOF

        cat << EOF > /etc/postfix/header_check
/From:.*/ REPLACE From: $displayname <$senderaddress>
EOF

        cat << EOF > /etc/postfix/sender_canonical_maps
/.+/    $displayname <$senderaddress>
EOF

        if [ $smtpauth -gt 0 ]; then
            cat << EOF > /etc/postfix/sasl_passwd
[$smtphost]:$smtpport $username:$password
EOF
            postmap /etc/postfix/sasl_passwd > /dev/null 2>&1
            postmap /etc/aliases > /dev/null 2>&1
            chown root:root /etc/postfix/sasl_passwd
            chown root:root /etc/postfix/sasl_passwd.db
            chmod 0600 /etc/postfix/sasl_passwd
            chmod 0600 /etc/postfix/sasl_passwd.db

            cat << EOF >> /etc/postfix/main.cf
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
EOF
        fi

        ln -sf /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/postfix/cacert.pem 

        systemctl restart postfix.service

        pvesh set access/users/root@pam -email $recipientaddress
    fi
}

create_swap_pool(){
    log "Configuring swap storage"
    if ! pvesm status | grep swap > /dev/null; then
        if ! zfs list rpool/swap > /dev/null 2>&1 ; then
            zfs create -o com.sun:auto-snapshot:frequent=false -o com.sun:auto-snapshot:hourly=false -o com.sun:auto-snapshot:daily=false -o com.sun:auto-snapshot:weekly=false -o com.sun:auto-snapshot:monthly=false rpool/swap
        else
            zfs set com.sun:auto-snapshot:frequent=false com.sun:auto-snapshot:hourly=false com.sun:auto-snapshot:daily=false com.sun:auto-snapshot:weekly=false com.sun:auto-snapshot:monthly=false rpool/swap
            zfs inherit com.sun:auto-snapshot rpool/swap
        fi
        pvesm add zfspool swap --content images,rootdir --pool rpool/swap
    fi
}

ask_volblocksize(){
    if whiptail --title "SET DEFAULT BLOCKSIZE" \
    --backtitle "$PROG" \
    --yes-button "SET BLOCKSIZE" \
    --no-button "SKIP" \
    --yesno "Do you want to adjust the default blocksize on all zfspool storages?" 9 76 ; then
        setblocksize=1
        if ! volblocksize=$(whiptail  --title "SET DEFAULT BLOCKSIZE" --backtitle "$PROG" --inputbox "Please enter the desired blocksize for your zfspool storages." 9 76 $volblocksize 3>&1 1>&2 2>&3); then cancel_dialog; fi
    fi
}

set_default_volblocksize(){
    if [ $setblocksize -gt 0 ]; then
        log "Setting default volblocksize=16k to all zfspool storages"
        for storage in $(pvesm status | grep zfspool | cut -d' ' -f1); do
            pvesm set $storage --blocksize $volblocksize
        done
    fi
}

install_checkzfs(){
    log "Installing checkzfs to /usr/local/bin/checkzfs"
    wget -q --no-cache -O /usr/local/bin/checkzfs https://raw.githubusercontent.com/bashclub/check-zfs-replication/main/checkzfs.py
    chmod +x /usr/local/bin/checkzfs
    log "Installing check-snapshot-age to /usr/local/bin/check-snapshot-age"
    wget -q --no-cache -O /usr/local/bin/check-snapshot-age https://raw.githubusercontent.com/bashclub/check-zfs-replication/main/check-snapshot-age
    chmod +x /usr/local/bin/check-snapshot-age
}

install_zsync(){
    log "Installing bashclub-zsync"
    wget -q --no-cache -O /usr/bin/bashclub-zsync https://git.bashclub.org/bashclub/zsync/raw/branch/main/bashclub-zsync/usr/bin/bashclub-zsync
    chmod +x /usr/bin/bashclub-zsync
    cat << EOF > /etc/logrotate.d/bashclub-zsync
/var/log/bashclub-zsync/*.log {
    weekly
    rotate 12
    compress
    delaycompress
    missingok
    notifempty
    create 644 root root
}
EOF
    mkdir -p /var/log/bashclub-zsync
    cat << EOF > /etc/cron.d/bashclub-zsync
#00 23 * * * root /usr/bin/bashclub-zsync -c /etc/bashclub/zsync.conf > /var/log/bashclub-zsync/zsync.log
EOF
}

virtiowin_updater() {
    log "Installing virtio-win-updater"
    cat << EOF > /usr/local/bin/virtio-win-updater
#!/bin/bash
#
# This script updates the virtio-win iso in Proxmox local storage
content=\$(wget -q -O - https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/)
server=https://fedorapeople.org
path=\$(echo -e "\$content" | grep -m1 title | cut -d "<" -f2 | cut -d " " -f3)
file=\$(echo -e "\$content" | grep -Eo "virtio-win-0.1.[0-9]+.iso" | grep -m1 virtio)
url=\$server\$path/\$file
if ! find /var/lib/vz/template/iso/\$file > /dev/null 2>&1 ; then
    echo "\$(date) New version available. Downloading \$file."
    wget -q -O /var/lib/vz/template/iso/\$file \$url
    old_virtio=\$(find /var/lib/vz/template/iso/ -name virtio-win* | grep -v \$file)
    if [ \$? -eq 0 ]; then
        for line in \$old_virtio; do
            if ! grep \$(echo \$line | cut -d'/' -f7) /etc/pve/qemu-server/* ; then
                echo "\$(date) Deleting \$line."
                rm -f \$line
            else
                echo "\$(date) Keeping \$line - Still in use by VMs."
            fi
        done
    fi
else
    echo "\$(date) Already on the current stable version: \$file."
fi
EOF
    chmod +x /usr/local/bin/virtio-win-updater
    rm -f /etc/cron.daily/virtio-win-updater
    cat << EOF > /etc/cron.daily/virtio-win-updater
#!/bin/bash
/usr/local/bin/virtio-win-updater >> /var/log/virtio-win-updater.log 2>&1
EOF
    cat << EOF > /etc/logrotate.d/virtio-win-updater
/var/log/virtio-win-updater.log {
    weekly
    rotate 12
    compress
    delaycompress
    missingok
    notifempty
    create 644 root root
}
EOF
    log "Running virtio-win-updater"
    virtio-win-updater
}

installation_task(){
    log "Starting Installation"

    set_locales
    set_pve_repo
    set_ceph_repo
    update_system
    install_tools
    enable_sdn
    set_arc_cache
    set_swappiness
    set_auto_snapshot
    pve_conf_backup
    suppress_no_subscription_warning
    harden_ssh
    install_checkzfs
    install_zsync
    set_mail_delivery
    create_swap_pool
    set_default_volblocksize
    virtiowin_updater

    log "Updating initramfs - This will take some time..."
    update-initramfs -u -k all > /dev/null 2>&1

}

summary(){
    autosnap=""
    for interval in "${!auto_snap_keep[@]}"; do
        autosnap="${interval}=${auto_snap_keep[$interval]} ${autosnap}"
    done

    if whiptail --title "POSTINSTALL SUMMARY" \
    --backtitle $PROG \
    --yes-button "INSTALL" \
    --no-button "ABORT & EXIT" \
    --yesno "Summary: \n\
    zfs_arc_min: $ZFS_ARC_MIN_MEGABYTES MB\n\
    zfs_arc_max: $ZFS_ARC_MAX_MEGABYTES MB\n\
    swappiness: $SWAPPINESS %\n\
    locales: $locales\n\
    repository: $repo_selection \n\
    subscription: $(pvesubscription get | grep status | cut -d' ' -f2)\n\
    suppress subscription warning: $suppress_warning\n\
    auto-snapshot: $autosnap\n\
    ssh-hardening: $ssh_hardening\n\
    mail delivery: $mailconfig
    sender email: $senderaddress
    sender display name: $displayname
    notification address: $recipientaddress
    smarthost: $smtphost
    smarthost port: $smtpport
    smarthost auth: $smtpauth
    smarthost username: $username
    set blocksize: $setblocksize
    volblocksize: $volblocksize
    " 30 76 ; then
        installation_task
    else
        cancel_dialog
    fi
}

source /etc/os-release

# Calculate and suggest values for ZFS L1ARC cache
arc_suggestion

# Set swapping behaviour
vm_swappiness

# Ask for additional locales 
ask_locales

# Ask for ssh hardening
ask_ssh_hardening

# Configure count per interval of zfs-auto-snapshot
auto_snapshot

# Select proxmox repository
select_pve_repo

# Select Ceoh repository
select_ceph_repo

# subscription related actions
select_subscription

# mail delivery config
ask_mail_config

# set volblocksize 
ask_volblocksize

summary

log "Proxmox postinstallation finished!"